Ballistically stabilized white phosphorus shell



Nov. 1, 1966 R. l. WESSELLS 3,282,714

BALLISTICALLY STABILIZED WHITE PHOSPHORUS SHELL Filed Nov. 2. 1964INVENTOR.

m w a W lw w., Rm 4 BY 6% l n; I W E Q/ 91 a G ATTORNEYS 3,282,714BALLHSTTCALLY STABILIZED WHITE PHQSPHORUS SHELL Russell 1. Wessells,Baltimore, Md., assignor to the United tates of America as representedby the Secretary of the Army Filed Nov. 2, 1964, Ser. No. 403,444 3Claims. (Cl. 102-66) The invention described herein may be manufacturedand used by or for the Government of the United States of America forgovernmental purposes without the payment to me of any royalty thereon.

This invention relates to munitions, and more particularly to means forflight stabilizing white phosphorus filled projectiles or shells whichdisseminate the white phosphorus upon impact with a target.

The main object of the invention is the provision of a projectileburster casing that has formed about its outer surface a plurality offins or impellers of which the main purpose is to ballisticallystabilize a white phosphorus filled projectile.

A further object of this invention is to ballistically stabilize a whitephosphorus filled projectile when the white phosphorus is in a liquidstate. The principle involved is to force the liquid white phosphorus toobtain the same, or nearly the same spin rate or angular velocity asthat of the projectile and to eliminate any forces that the liquid whitephosphorus may set up within the projectile that would cause it to yawor tumble in flight and fall short of the intended range. It is to benoted here that the name white phosphorus hereinafter will be referredto, or be called, by its other well known short designation WP. Whitephosphorus is also called yellow phosphorus.

The problem of projectile stabilization has existed for many years andhas become more critical in the modern thin-wall projectiles, in whichcase the weight of the projectile is proportionately small compared tothe weight of the WP filler. Projectiles filled with the WP must beballistically stable over temperature range from 65 F. to 140 F. Whitephosphorus becomes a liquid at temperatures above 112.1 F. (445 C.) andhas a density of 1.745.

Various methods were exploited in the past to remedy the existingdeficiencies in projectile stabilization. For example, internal bafiies,or vanes and bellows have been fastened to the walls of projectiles inan elfort to flight stabilize the latter when WP Was in liquid state.None of the above mentioned methods that were tried proved to besuccessful. Moreover, the numerous devices that were tried, weredifficult to insert or fasten within the projectile. Furthermore, thefastening of these devices to projectile walls interfered with theformation of a void space. A projectile or shell cannot be completelyfilled with WP, since a space or void must be provided for expansionwhen the projectile is heated. This void adds to the problem of flightstabilization.

For example, WP shells must be stored upright for best results becauseif they are left horizontal in the hot sun or stored under tropicconditions, the WP melts and when it hardens again the void will besomewhere on the side of the shell. When this shell is subsequentlyfired in a rifled cannon, the high revolutions per minute (approximately25,000 r.p.m.) imparted to the projectile by the action of the riflingbands on the rifled bore, will cause the projectile to wobble or tumblein flight. This greatly reduces the expected range of the weapon and hascaused casualties to friendly troops rather than enemy troops. Myinvention will not correct the problem of improper storage but it willtend to prevent the ballistic problem that arises when these shells arefired since the fins provided by my tates Patent 3,282,714 Patented Nov.1, 1966 invention tend to act as a heat sink in the center of the moltenWP. When this mass is cooling off, there is evidence to show that thevoid forms at or near the fins in the approximate center of gravity ofthe shell rather than at the extreme inside surface of the shell. Thus,my invention will stabilize liquid (or hot) WP shells and solid (orcold) WP shells that have been improperly stored.

Projectiles containing the finned type burster casings were tested andproven to be ballistically stable at all ranges and at the requiredtemperatures of -6S F. to F. The fins or the impellers of the burstercasing succeeded in acceleration of the liquid WP to the same or nearlythe same rate as that of the projectile itself.

Other more important advantages of my invention are that the fins servethe purpose of preventing the free longitudinal movement or oscillationof the liquid WP, that the fins swirl the liquid WP in flight so thatthe void is reduced to a thin vortex on the axis of rotation of theshell, and that the fins force the WP to act substantially the same as asolid substance.

A still further advantage of my invention is that in mass production ofammunition it is desirable to have one basic shell which can be adaptedto suit various requirements rather than have several specialized shellswhich must be supplied in limited production. My invention supplies thisneed since the empty shell can be supplied in lots of a million or moreand be used as high explosive rounds or WP rounds without extensive andexpensive modification of the basic shell.

Other objects and advantages of this invention will become apparent asthe following description is read in connection with the accompanyingdrawing in which:

FIGURE 1 is a sectional view of a projectile showing the finnedprojectile burster casing.

FIGURE 2 is a cross sectional view taken at 22 showing a plurality offins.

FIGURE 3 is a diagrammatic view of a shell combined with the shellcasing.

Referring to the drawing, 10 designates the projectile or shell bodywhich is provided with a pair of riding bands 11, a base plug 13 havinga tracer (or dummy of equal weight) 15 and a burster casing 17containing a rotationally armed impact fuze 19, booster charge 20, andburster charge 21 respectively. The fuze, booster, and the burster maybe of any suitable conventional type as those for example which areshown and described in the US. patent to Weeke, No. 1,417,475. Thebottom of the well portion of the burster casing 17 has extruded orfastened onto it a plurality of 3-12 (preferably 6) radial andlongitudinally extending straight fins or impellers 23.

The projectile 10 is filled with molten white phosphorus 25 and theburster casing 17 is force-fitted within the latter thereby creating aleak-proof joint at 27. Thus, the WP is sealed within the projectile bymeans of the interference fit between the burster casing and the shellwalls. The shell 10 is contained within a shell casing 29.

This invention also enables the present US. Army standard projectilecasing to be easily modified to become a WP projectile or a highexplosive (HE) projectile. The WP projectile therefore becomesinterchangeable with the standard HE projectile when using my invention.This means that the HE projectile can be fired and be followedimmediately with the firing of a WP projectile without any gun sitecorrections being made. It is highly desirable, if not mandatory, thatthese two types of ammunition be identical in weight and external shapeand be a ballistic match over all flight zones. This has beenaccomplished by adding fins or impellers to the burster casing. Thisinvention can be used in any caliber gun in which a modern thin walledshell is being used such as the 75, 105, 152 and mm. types. The problemwhich this invention solves is particularly acute in 105 mm. tankmounted guns Where the ammunition frequently is subjected totemperatures above the melting point of WP as for example under desertconditions.

It will, of course, be understood that various details of constructionsuch as the number of fins 23 may be varied through a wide range Withoutdeparting from the principles of this invention and I therefore do notwish to be limited to the details shown and described.

I claim:

1. A phosphorus disseminating projectile comprising:

(1) a hollow ogive-shape-d body means having an opening in the base end;

(2) burster casing means mounted in sealing relationship With saidopening and extending a predetermined axial distance interiorly of saidbody;

(a) said casing means having fuze means sealed therein adjacent to saidopening;

(b) said casing means having a portion thereof containing explosivemeans remote from said opening and detonatably connected to said fuze;

(c) said casing means having a plurality of radially and longitudinallyextending fin means being wholly supported by and integral with saidexplosive charge portion.

2. A phosphorus disseminating projectile comprising in combination:

(1) a hollow ogive-shaped body having an axial opening in the base end;

(2) a burster casing mounted in sealing relationship with said openingand extending a predetermined axial distance interiorly of said body;

(a) said casing having a fuze sealed therein adjacent to said opening;

(b) said casing having a portion thereof containing a burster chargeremote from said opening and detonatably connected to said fuze;

(c) said casing having a plurality of radially and longitudinallyextending fins being Wholly supported by and integral With said burstercharge portion.

3. In a phosphorus disseminating projectile comprising a hollow,ogive-shaped body having an axially located, longitudinally extendingburster casing with a fuze and burster charge therein sealing the baseend of said body, the improvement which comprises providing said burstercasing with a plurality of radially and longitudinally extending finswhich are Wholly supported by and integral with said burster casing.

References Cited by the Examiner UNITED STATES PATENTS 1,311,521 7/1919Johnson 102-66 1,819,106 8/1931 McBride et a1. 102-66 3,103,888 9/1963Rosenthal 102-66 References (Iited by the Applicant UNITED STATESPATENTS 1,417,475 5/1922 Weeke. 1,878,491 9/1932 Goss. 2,774,305 12/1956 Fitzgerald et a1.

SAMUEL FEINB-ERG, Primary Examiner.

FRED C. MATTERN, JR., Examiner.

W. KUJAWA, Assistant Examiner.

1. A PHOSPHORUS DISSEMINATING PROJECTILE COMPRISING: (1) A HOLLOW OGIVE-SHAPED BODY MEANS HAVING AN OPENING IN THE BASE END; (2) BURSTER CASING MEANS MOUNTED IN SEALING RELATIONSHIP WITH SAID OPENING AND EXTENDING A PREDETERMINED AXIAL DISTANCE INTERIORLY OF SAID BODY; (A) SAID CASING MEANS HAVING FUZE A PORTION THEREOF THEREIN ADJACENT TO SAID OPENING; (B) SAID CASING MEANS HAVING A PORTION THEREOF CONTAINING EXPLOSIVE MEANS REMOTE FROM SAID OPENING AND DETONATABLY CONNECTED TO SAID FUZE; (C) SAID CASING MEANS HAVING A PLURALITY OF RADIALLY AND LONGITUDINALLY EXTENDING FIN MEANS BEING WHOLLY SUPPORTED BY AND INTEGRAL WITH SAID EXPLOSIVE CHARGE PORTION. 